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(No Model.) u

E. M. FOX 8v L. K. BOEM.

BLBGTRIG'LAMP.

No. 248,156. Patented Oct. 11,1881.

INVBNTOR m.

WITNE Jy OLT/Mw ATTORNEYS.

N. PETERS. Phdwihogmphnr. Wnhingmn. DA C.

UNITED STATES PATENT CEEICE.

EDWIN M. FOX AND LUDVIG K. BIIM, OF NEW YORK, N. Y., ASSIGNCRS TO THE AMERICAN ELECTRIC LIGHT COMPANY, OF' SAME PLACE.

ELECTRIC LAMP.

SPECIFICATION forming part of Letters Patent No. 248,156, dated october 11, 1881.

Application filed July 6, 1881. (No model.)

To all whom it may concern Beit known that we, EDWIN M. FOX and LUDWIG K. BHM, of the city, county, and State of' New York, have invented a certain new andusefulImprovementinElectricLamps; ot' which the following is a speciiication.

Our improvements relate to electric lamps for which vacuum-chambers are employed, and have i'or their object to facilitate the insertion and removal of the carbon, as well as the operation of drawing the vacuum, and to dispense with the usual operation ofV sealing the drawing-nipple by melting.

Our invention consists in the combination of a vacuum-chamber formed with aneck and a sealing plug or stopper, having its longitudinal axis coincident with the longitudinal axis of the neck, and bearing the conducting-wires, both the stopper and the neck being formed with openings arranged to be turned into or out of registration, to permit the lamp to be lirst exhausted and then sealed, as hereinafter fully described.

ln the accompanying drawings, Figure l is a sectional elevation ot' a lamp embodying our invent-ion. Fig. 2 is a erosssection on lineman oflig. 1. The other ligures show certain modilications, referred to hereinafter.

Similar letters of reference indicate correspondin g parts.

A is the globe, which may be of any usual or desired form, and is formed with the tubular neck portion a. The end of neck a is closed either by a tapering pin or plug, or by a socketpiece into which the tube enters to form an air-tight but separable joint. In Fig.1 the end of the tube a. is closed by a tapering glass plug, b, and the contact-surfaces of the plug and tube are ground to form a perfect joint. The wires c c pass through the plug b lengthwise ofthe same, the glass being sea-led tightly around the wires.' The plug b is formed with a passage, e, which opens at the inner end of the tube, and also at one side on the ground portiomt'orming the join t. The tube l is formed with a stem or nipple, f, at one side, in such position that it can be madeto coincide with the end ot' passage e. By these means an open ing from the outside to the interior ofthe chamber can be had by turning the plug or the lamp, and such opening cut ott' in the same manner.

To exhaust the chamber the plug, having the wires and carbon attached, is first put in place, with the aperture e coinciding with the nipple. The pump is then attached to the nipple and the air drawn, after which, by a parf tial turn of the plug or the globe, the passage is closed, and the exhausted globe thus hermetically sealed. The same operation is repeated in case the plug is removed for renewal of the carbon.

In Fig. 3 the plug l) is cup-shaped, and in that. case the side is simply apertured at c to coincide with thc nipple j' ot' the neck. In Fig. et the plug is made hollow, or as a tapering socket, that receives the end of neck a, and in that case the drawing-nipplefis formed on the socket, and the neck a is apertured at c. The adjacent edges of this socket-shaped stopple and the neck are suitably ground, and to insure a tight joint the upper edge ot' the stopple is enlarged to form an annular trough, which receives a scaling liquid-such as mercurywhich trough is closed by a packing-ring 'interposed between the neck of the lamp and the edge ot' the stopple. In any of these forms the plug may belitted in a suitable stand, and thus support the lamp, or the lamp may be supported or suspended in any suitable manner.

In defining more clearly the limits of our invention as claimed in this patent, we would state that we onlyhere claim the apertured stopperin combination with the vacuum-chamber when said apertured stopper bears the conducting-wires and sustains the carbon or its equivalent.

Ve are aware that a broader claim might be predicated on our device, in which the supporting of the wires upon the stopper might be dispensed with, and the wires introduced as shown in dotted lines in Figs. l and 3. We do not make this claim in this patent, however. We are aware also that specific claims might be made on the peculiar form of cup-shaped and apertured stopper shown in Fig. 4, but do not make such claims in this patent. Both these features we regard as patentable p0rtions ot'our invention, and We reserve the right to cover these hereafter in a separate application.

Having thus fully described our invention, we claim as new and desire to secure by Letters Patent- 1. In an electric lamp, the combination ot' the Vacuum-chamber formed with a neck and a sealing plug or stopper, having,` its longitudinal axis coincident with the longitudinal axis ofthe neck, and bearing` the conductingwires, both the stopper and the neck being;

auslst formed with openings, as described, arranged to be turned into or out of registration, to perinitJ the lamp to be first exhausted and then sealed, as and for the purpose set forth.

2. The combination, with the vaeuumehuinher A, having' tubular neck a, provided with draining or exhaust tube f, ot' sealing-plug.;l b, formed with aperture e and carrying the cond ucting-wires and cnrbon, sul'istantially as and for the purposes set forth.

EDVIN M. FOX. LUDVIG K. BOHM. 4Witnesses:

GEO. D. WALKER, C. SEDGWICK. 

